Consistency of GPS and strong-motion records: case study of Mw9.0 Tohoku-Oki 2011 earthquake

TL;DR

This study evaluates the consistency between GPS and strong-motion records during the Tohoku 2011 earthquake, highlighting how their agreement varies with frequency, source distance, and excitation direction.

Contribution

It provides a comprehensive comparison of GPS and strong-motion data in the frequency domain for a major earthquake, revealing factors influencing their consistency.

Findings

Consistency depends on excitation frequency

Direction of excitation affects data agreement

Distance from source influences record compatibility

Abstract

GPS and strong-motion sensors are broadly used for the monitoring of structural health and Earth surface motions, focusing on response of structures, earthquake characterization and rupture modeling. Most studies have shown differences between the two systems at very long periods (e.g. >100sec). The aim of this study is the assessment of the compatibility of GPS and strong-motion records by comparing the consistency in the frequency domain and by comparing their respective displacement waveforms for several frequency bands. For this purpose, GPS and strong-motion records of 23 collocated sites of the Mw9.0 Tohoku 2011 earthquake were used to show that the consistency between the two datasets depends on the frequency of the excitation, the direction of the excitation signal and the distance from the excitation source.